No Swift was developed as a strategic moat around Apple's devices. They cannot be dependent on any other party for the main language that runs on their hardware. Controlling your own destiny full stack means having your own language.

Apple already had that "strategic moat" with Objective-C. It was already a language you could effectively only use on Apple platforms (the runtime and the standard library only run on Darwin) and for which Apple controlled the compiler (they have their own fork of Clang).